The advancement of retinal research has been on the fast track to making a true breakthrough in eye health. Researchers at the USC Roski Eye Institute have collaborated with other California institutions to show that a first-in-kind stem cell-based retinal implant is feasible for use in people with advanced dry age-related macular degeneration.

The treatment consists of a layer of human embryonic stem cell–derived retinal pigment epithelium cells on an very thin supportive structure, was implanted in the retina of four patients by a USC surgeon. The patients were followed for one year to assess its safety. There were no severe adverse effects related to the implant or the surgical procedure, indicating that the treatment was well-received. There was also evidence that the implant integrated with the patients’ retinal tissue, which is essential for the treatment to be able to improve visual function.

Dry age-related macular degeneration is the most common type of age-related macular degeneration. Over time, it can lead to loss of central vision, which can diminish people’s ability to perform daily tasks like reading, writing, driving and seeing faces. Age-related macular degeneration affects approximately 1.7 million Americans and is projected to rise to almost 3 million by 2020. It is a leading cause of severe visual impairment in adults older than 65.

As part of the study, the researchers also performed a preliminary assessment of the therapy’s efficacy. One patient had improvement in visual acuity, which was measured by how many letters they could read on an eye chart, and two patients had gains in visual function, which was measured by how well they could use the area of the retina treated by the implant. None of the patients showed evidence of progression in vision loss.

“This is the first human trial of this novel stem cell–based implant, which is designed to replace a single-cell layer that degenerates in patients with dry age-related macular degeneration,” says lead author and surgeon for the study Amir H. Kashani, MD, PhD, assistant professor of clinical ophthalmology at the Keck School of Medicine of USC. “This implant has the potential to stop the progression of the disease or even improve patients’ vision. Proving its safety in humans is the first step in accomplishing that goal.”